kernel.git/security/smack/smack.h, branch linux-3.12.y

Smack: network label match fix

2013-08-02T03:04:02Z

The Smack code that matches incoming CIPSO tags with Smack labels reaches through the NetLabel interfaces and compares the network data with the CIPSO header associated with a Smack label. This was done in a ill advised attempt to optimize performance. It works so long as the categories fit in a single capset, but this isn't always the case. This patch changes the Smack code to use the appropriate NetLabel interfaces to compare the incoming CIPSO header with the CIPSO header associated with a label. It will always match the CIPSO headers correctly. Targeted for git://git.gitorious.org/smack-next/kernel.git Signed-off-by: Casey Schaufler

security: smack: add a hash table to quicken smk_find_entry()

2013-08-01T23:55:20Z

Accepted for the smack-next tree after changing the number of slots from 128 to 16. This patch adds a hash table to quicken searching of a smack label by its name. Basically, the patch improves performance of SMACK initialization. Parsing of rules involves translation from a string to a smack_known (aka label) entity which is done in smk_find_entry(). The current implementation of the function iterates over a global list of smack_known resulting in O(N) complexity for smk_find_entry(). The total complexity of SMACK initialization becomes O(rules * labels). Therefore it scales quadratically with a complexity of a system. Applying the patch reduced the complexity of smk_find_entry() to O(1) as long as number of label is in hundreds. If the number of labels is increased please update SMACK_HASH_SLOTS constant defined in security/smack/smack.h. Introducing the configuration of this constant with Kconfig or cmdline might be a good idea. The size of the hash table was adjusted experimentally. The rule set used by TIZEN contains circa 17K rules for 500 labels. The table above contains results of SMACK initialization using 'time smackctl apply' bash command. The 'Ref' is a kernel without this patch applied. The consecutive values refers to value of SMACK_HASH_SLOTS. Every measurement was repeated three times to reduce noise. | Ref | 1 | 2 | 4 | 8 | 16 | 32 | 64 | 128 | 256 | 512 -------------------------------------------------------------------------------------------- Run1 | 1.156 | 1.096 | 0.883 | 0.764 | 0.692 | 0.667 | 0.649 | 0.633 | 0.634 | 0.629 | 0.620 Run2 | 1.156 | 1.111 | 0.885 | 0.764 | 0.694 | 0.661 | 0.649 | 0.651 | 0.634 | 0.638 | 0.623 Run3 | 1.160 | 1.107 | 0.886 | 0.764 | 0.694 | 0.671 | 0.661 | 0.638 | 0.631 | 0.624 | 0.638 AVG | 1.157 | 1.105 | 0.885 | 0.764 | 0.693 | 0.666 | 0.653 | 0.641 | 0.633 | 0.630 | 0.627 Surprisingly, a single hlist is slightly faster than a double-linked list. The speed-up saturates near 64 slots. Therefore I chose value 128 to provide some margin if more labels were used. It looks that IO becomes a new bottleneck. Signed-off-by: Tomasz Stanislawski

Smack: Add smkfstransmute mount option

2013-05-28T17:08:44Z

Suppliment the smkfsroot mount option with another, smkfstransmute, that does the same thing but also marks the root inode as transmutting. This allows a freshly created filesystem to be mounted with a transmutting heirarchy. Targeted for git://git.gitorious.org/smack-next/kernel.git Signed-off-by: Casey Schaufler

Smack: Improve access check performance

2013-05-28T17:08:32Z

Each Smack label that the kernel has seen is added to a list of labels. The list of access rules for a given subject label hangs off of the label list entry for the label. This patch changes the structures that contain subject labels to point at the label list entry rather that the label itself. Doing so removes a label list lookup in smk_access() that was accounting for the largest single chunk of Smack overhead. Targeted for git://git.gitorious.org/smack-next/kernel.git Signed-off-by: Casey Schaufler

Smack: Local IPv6 port based controls

2013-05-28T17:08:26Z

Smack does not provide access controls on IPv6 communications. This patch introduces a mechanism for maintaining Smack lables for local IPv6 communications. It is based on labeling local ports. The behavior should be compatible with any future "real" IPv6 support as it provides no interfaces for users to manipulate the labeling. Remote IPv6 connections use the ambient label the same way that unlabeled IPv4 packets are treated. Targeted for git://git.gitorious.org/smack-next/kernel.git Signed-off-by: Casey Schaufler

smack: SMACK_MAGIC to include/uapi/linux/magic.h

2013-03-19T21:16:15Z

SMACK_MAGIC moved to a proper place for easy user space access (i.e. libsmack). Signed-off-by: Jarkko Sakkinen

Smack: onlycap limits on CAP_MAC_ADMIN

2012-07-13T22:49:23Z

Smack is integrated with the POSIX capabilities scheme, using the capabilities CAP_MAC_OVERRIDE and CAP_MAC_ADMIN to determine if a process is allowed to ignore Smack checks or change Smack related data respectively. Smack provides an additional restriction that if an onlycap value is set by writing to /smack/onlycap only tasks with that Smack label are allowed to use CAP_MAC_OVERRIDE. This change adds CAP_MAC_ADMIN as a capability that is affected by the onlycap mechanism. Targeted for git://git.gitorious.org/smack-next/kernel.git Signed-off-by: Casey Schaufler

Smack: fix smack_new_inode bogosities

2012-07-13T22:49:23Z

In January of 2012 Al Viro pointed out three bits of code that he titled "new_inode_smack bogosities". This patch repairs these errors. 1. smack_sb_kern_mount() included a NULL check that is impossible. The check and NULL case are removed. 2. smack_kb_kern_mount() included pointless locking. The locking is removed. Since this is the only place that lock was used the lock is removed from the superblock_smack structure. 3. smk_fill_super() incorrectly and unnecessarily set the Smack label for the smackfs root inode. The assignment has been removed. Targeted for git://gitorious.org/smack-next/kernel.git Signed-off-by: Casey Schaufler

Merge branch 'master' of git://git.infradead.org/users/eparis/selinux into next

2012-05-22T01:21:06Z

Per pull request, for 3.5.

Smack: allow for significantly longer Smack labels v4

2012-05-15T05:48:38Z

V4 updated to current linux-security#next Targeted for git://gitorious.org/smack-next/kernel.git Modern application runtime environments like to use naming schemes that are structured and generated without human intervention. Even though the Smack limit of 23 characters for a label name is perfectly rational for human use there have been complaints that the limit is a problem in environments where names are composed from a set or sources, including vendor, author, distribution channel and application name. Names like softwarehouse-pgwodehouse-coolappstore-mellowmuskrats are becoming harder to avoid. This patch introduces long label support in Smack. Labels are now limited to 255 characters instead of the old 23. The primary reason for limiting the labels to 23 characters was so they could be directly contained in CIPSO category sets. This is still done were possible, but for labels that are too large a mapping is required. This is perfectly safe for communication that stays "on the box" and doesn't require much coordination between boxes beyond what would have been required to keep label names consistent. The bulk of this patch is in smackfs, adding and updating administrative interfaces. Because existing APIs can't be changed new ones that do much the same things as old ones have been introduced. The Smack specific CIPSO data representation has been removed and replaced with the data format used by netlabel. The CIPSO header is now computed when a label is imported rather than on use. This results in improved IP performance. The smack label is now allocated separately from the containing structure, allowing for larger strings. Four new /smack interfaces have been introduced as four of the old interfaces strictly required labels be specified in fixed length arrays. The access interface is supplemented with the check interface: access "Subject Object rwxat" access2 "Subject Object rwaxt" The load interface is supplemented with the rules interface: load "Subject Object rwxat" load2 "Subject Object rwaxt" The load-self interface is supplemented with the self-rules interface: load-self "Subject Object rwxat" load-self2 "Subject Object rwaxt" The cipso interface is supplemented with the wire interface: cipso "Subject lvl cnt c1 c2 ..." cipso2 "Subject lvl cnt c1 c2 ..." The old interfaces are maintained for compatibility. Signed-off-by: Casey Schaufler